Justice
Michael Sandel's famous introduction to moral and political philosophy, one of the most popular courses ever taught at Harvard College, now hosted on edX with a free audit track. The course works through Aristotle, Locke, Kant, Mill, and Rawls, applying their frameworks to affirmative action, the distribution of income, same-sex marriage, market limits, and human and property rights, using Sandel's Socratic classroom method to force a position before revealing the philosophical stakes. Auditing gives free access to the lecture videos, discussion forums, and most course activities, with the paid track adding a certificate and some graded exercises. Sandel has been called a rock-star moralist by Newsweek for his ability to fill stadiums with this material. It is the closest thing philosophy has to a mass-audience blockbuster, taught by the person who wrote it.